1. Field of the Invention
The present invention is generally related to surgical devices and methods, and in particular, provides a self-closing surgical valve capable of deforming to pass objects both proximally and distally, particularly for accessing an internal surgical site during laparoscopic and other minimally invasive surgical procedures.
Minimally invasive surgical procedures have gained wide acceptance in the areas of general and gynecological surgery. Minimally invasive techniques are now being developed for therapies of the heart, lung, kidney, and the like. Generally, these procedures make use of one or more small incisions (or other openings) to access internal tissues, often through a cannula, trocar, or other access device. Gas insufflation or fluid distension may be used to enhance the available space within the internal surgical site, and the therapy is often directed with reference to an image provided by an endoscope, a microscope, or using a remote imaging modality such as fluoroscopy, ultrasound, or the like. Generally, minimally invasive surgical procedures minimize patient trauma and speed recovery over traditional open surgical procedures.
Unfortunately, many surgical techniques are difficult to accomplish through laparoscopic cannulas or other minimally invasive access devices. It is sometimes desirable to remove relatively large masses of tissue, for example, to remove a kidney, a partial lung resection, or the like. Removing such large tissue masses laparoscopically through a small access lumen is fairly difficult and time consuming.
Specialized devices have recently been proposed to sever large tissue masses into segments, which are more easily removed. These devices generally include a rotating tube having a sharpened distal end which extends through a fixed outer tube. This sharpened end is inserted into the patient through a cannula, or directly through an incision. The surgeon inserts a grasping device (such as endoscopic forceps or a laparoscopic grasper) through the rotating tube. Grasping the large mass of tissue to be removed, the surgeon pulls the tissue up into the tube, so that the rotating edge severs the grasped portion from the large mass. The size of the severed tissue is generally limited by the outline of the rotating edge, so that the surgeon can continue to pull the severed tissue out of the patient through the rotating tube. By repeating the grasping and severing procedure, surgeons can remove relatively large masses of tissue quite quickly. As the large tissue mass is removed in small, individually grasped morcels, these devices are often referred to as "morcellators".
Although rotating tube morcellators represent a significant advancement in minimally invasive surgical procedures for removing large tissue masses, these known devices still have several significant drawbacks. It is often desirable to maintain pneumo-peritoneum (abdominal distention using pressurized gas) during the resection procedure. Although duck-bill and other laparoscopic valves are available to prevent the insufflation gas from flowing through the morcellator lumen, removal of tissues through these known self-closing valves is generally somewhat problematic. Specifically, duck-bill valves usually deform to pass graspers and other surgical implements distally through the morcellator, but work in connection with the present invention as shown that these duck-bill structures tend to catch on the large severed tissue morsels as they are drawn proximally through the valve. This can lead to failure of the valve and loss of pneumo-peritoneum, resulting in a considerable delay while the failed valve is removed and replaced and the abdomen is once again distended with insufflation gas.
In light of the above, it would be desirable to provide improved valve structures and sealing methods, particularly for use in minimally invasive surgical procedures. It would be particularly desirable if these improved valve structures were better adapted for passing objects both distally and proximally. It would further be desirable if such improved valve structures provided the pressure enhanced sealing and self-closure of known duck-bill valve structures, so as to be easily adapted for sealing insufflation gas during laparoscopy, and for a wide variety of additional minimally invasive surgical uses.
2. Description of the Background Art
Sealing structures for cannulas, trocars, and other minimally invasive surgical devices are described in U.S. Pat. No. 5,401,248, No. 5,391,153, No. 4,909,798, No. 5,603,702, No. 5,180,373, No. 5,141,498, No. 5,514,098, No. 5,496,280, No. 5,441,486, No. 5,429,609, No. 5,397,314, No. 5,389,080, No. 5,385,552, No. 5,380,288, No. 5,356,394, No. 5,354,280, No. 5,330,437, No. 5,312,362, No. 5,300,033, No. 5,269,764, No. 5,263,944.